Leucostoma
Canker (fungus - Leucostoma cinata - anamorph Cytospora leucostoma):
The fungus is a weak pathogen and is rarely a problem in well managed orchards
with rapidly growing trees. Pimple-like bumps develop on the surface of cankers.
During the growing season small streams of gum are formed at each pimple. In most
cases a callus layer forms around the damaged area and the canker is walled off.
In a few cases the canker growth will resume in the fall after the callus growth
is slowed. Leucostoma canker may become established in a limb through pruning
cuts or sunburn injury. Affected trees should be pruned to remove the canker sites
and fertilized to promote growth.
